Cleanups.

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
===================================================================
--- runtime/vm/flow_graph_builder.cc	(revision 9794)
+++ runtime/vm/flow_graph_builder.cc	(working copy)
@@ -385,10 +385,12 @@
   return;
 }
 
+
 void ValueGraphVisitor::VisitLiteralNode(LiteralNode* node) {
   ReturnComputation(new ConstantVal(node->literal()));
 }
 
+
 // Type nodes only occur as the right-hand side of instanceof comparisons,
 // and they are handled specially in that context.
 void EffectGraphVisitor::VisitTypeNode(TypeNode* node) { UNREACHABLE(); }
@@ -2535,7 +2537,7 @@
     Bailout("Catch-entry support in SSA.");
   }
   // TODO(fschneider): Support copied parameters.
-  if (parsed_function().copied_parameter_count()) {
+  if (parsed_function().copied_parameter_count() != 0) {
     Bailout("Copied parameter support in SSA");
   }
   ASSERT(var_count == (parsed_function().stack_local_count() +
@@ -2565,16 +2567,6 @@
 }
 
 
-static intptr_t WhichPred(BlockEntryInstr* predecessor,
-                          JoinEntryInstr* join_block) {
-  for (intptr_t i = 0; i < join_block->PredecessorCount(); ++i) {
-    if (join_block->PredecessorAt(i) == predecessor) return i;
-  }
-  UNREACHABLE();
-  return -1;
-}
-
-
 // Helper to a copy a value iff it is a UseVal.
 static Value* CopyValue(Value* value) {
   return value->IsUse()
@@ -2619,17 +2611,16 @@
       // Update expression stack.
       ASSERT(env->length() > var_count);
       env->RemoveLast();
-      if (v->AsUse()->definition()->IsBind() &&
-          v->AsUse()->definition()->AsBind()->computation()->IsLoadLocal()) {
-        Computation* comp = v->AsUse()->definition()->AsBind()->computation();
+      BindInstr* as_bind = v->AsUse()->definition()->AsBind();
+      if ((as_bind != NULL) && as_bind->computation()->IsLoadLocal()) {
+        Computation* comp = as_bind->computation();
         intptr_t index = comp->AsLoadLocal()->local().BitIndexIn(var_count);
         current->SetInputAt(i, CopyValue((*env)[index]));
       }
-      if (v->AsUse()->definition()->IsBind() &&
-          v->AsUse()->definition()->AsBind()->computation()->IsStoreLocal()) {
+      if ((as_bind != NULL) && as_bind->computation()->IsStoreLocal()) {
         // For each use of a StoreLocal: Replace it with the value from the
         // environment.
-        Computation* comp = v->AsUse()->definition()->AsBind()->computation();
+        Computation* comp = as_bind->computation();
         intptr_t index = comp->AsStoreLocal()->local().BitIndexIn(var_count);
         current->SetInputAt(i, CopyValue((*env)[index]));
       }
@@ -2684,7 +2675,8 @@
       block_entry->last_instruction()->SuccessorAt(0)->IsJoinEntry()) {
     JoinEntryInstr* successor =
         block_entry->last_instruction()->SuccessorAt(0)->AsJoinEntry();
-    intptr_t pred_index = WhichPred(block_entry, successor);
+    intptr_t pred_index = successor->IndexOfPredecessor(block_entry);
+    ASSERT(pred_index >= 0);
     if (successor->phis() != NULL) {
       for (intptr_t i = 0; i < successor->phis()->length(); ++i) {
         PhiInstr* phi = (*successor->phis())[i];